Wallius Mari-Anne, Rissanen Saara M, Bragge Timo, Vartiainen Paavo, Karjalainen Pasi A, Räsänen Kimmo, Järvelin-Pasanen Susanna
Institution of Public Health and Clinical Nutrition, Ergonomics, School of Medicine, University of Eastern Finland, Finland.
Ind Health. 2016;54(1):58-67. doi: 10.2486/indhealth.2015-0108. Epub 2015 Sep 30.
The aim of this study was to investigate effects of mop handle height on electromyographic (EMG) activities of the shoulder muscles and perceived exertion for the shoulder area during floor mopping using a figure eight method. An experimental study with 13 cleaners was conducted using surface EMG and category ratio (CR-10) scale. EMG activity was recorded unilaterally from the upper trapezius, infraspinatus, anterior and middle deltoid muscles. Each subject performed four trials of mopping and each trial consisted of using a different mop handle height (mop adjustment at the level of shoulder, chin, nose and eye) in randomized order. EMG data were normalized to a percentage of maximal voluntary contraction (%MVC). The muscle activities were assessed by estimating the 10th, 50th and 90th percentiles of the amplitude probability distribution function (APDF) of the EMG signals and analysed by linear mixed model analysis. Results showed that shoulder muscle activity was significantly lower when the mop handle height was adjusted to shoulder level or chin level as compared to eye level. These findings were supported by subjective ratings of exertion. It seems that mop handle height adjustment between shoulder and chin level may be recommended as a basis for figure eight mopping.
本研究旨在采用“8”字形拖地方法，调查拖把柄高度对拖地过程中肩部肌肉肌电图（EMG）活动及肩部区域主观用力感觉的影响。对13名清洁工人进行了一项实验研究，采用表面肌电图和类别比率（CR-10）量表。单侧记录上斜方肌、冈下肌、三角肌前束和中束的肌电图活动。每位受试者进行四次拖地试验，每次试验包括使用不同的拖把柄高度（拖把高度调整至肩部、下巴、鼻子和眼睛水平），顺序随机。肌电图数据以最大自主收缩百分比（%MVC）进行标准化。通过估计肌电图信号幅度概率分布函数（APDF）的第10、50和90百分位数来评估肌肉活动，并采用线性混合模型分析。结果表明，与眼睛水平相比，将拖把柄高度调整至肩部水平或下巴水平时，肩部肌肉活动显著降低。这些结果得到了主观用力评级的支持。似乎可以建议将拖把柄高度调整在肩部和下巴水平之间，作为“8”字形拖地的依据。
